1. Field of the Invention
An aspect of the present invention relates to a media independent handover (MIH) terminal and an MIH server, performing a vertical handover (VHO), and a method of the VHO by the MIH terminal and the MIH server. More particularly, an aspect of the present invention relates to an MIH terminal, an MIH server, and a method of a VHO by the MIH terminal and the MIH server which can maintain a quality of a communication service by minimizing a packet loss, occurring when performing the VHO, since the MIH server transmits temporary channel information of a second communication network to the MIH terminal. Accordingly; the MIH terminal can maintain a temporary channel connection to the second communication network, when performing the VHO from a first communication network to a second communication network.
2. Description of the Related Art
With the development of communication technologies, various communication services are popularized and widely used. A dual mode terminal, capable of supporting various communication services within a single terminal, becomes more popular as communication services become more diverse. The dual mode terminal may perform a handover between a code division multiple access (CDMA) communication network and a global system for mobile (GSM) communication network, and may perform a handover between a wideband code division multiple access (W-CDMA) communication network and the CDMA communication network.
A packet loss, caused by handover latency, is an important issue in performing the handover of the dual mode terminal. Namely, a loss of a transmitted/received packet may occur, since a normal communication can not be performed instantaneously, with any communication network when the handover latency occurs.
Particularly, the handover latency is greater in a handover between different devices than in a handover between devices of the same type since there are a number of additional processes which are required in a network in the handover between different devices. Also, it is an important issue to minimize the packet loss in the handover between the different devices when an amount of the packet loss is great.
Particularly, in a case of performing a VHO from a wireless LAN (WLAN) to another communication network, there is a tendency that retransmission is repeatedly performed until transmission is successful when transmitting of WLAN medium access control (MAC) protocols. Accordingly, a waste of wireless resources between a terminal and a wireless local area network access point (WLAN AP) may become great.
Thus, a method of a VHO which can improve the quality of the communication service and can prevent the waste of the network resource by minimizing the packet loss when performing the VHO, is required.